Field of the Invention
Embodiments of the invention relate to electronic systems and, in particular, to radio frequency (RF) electronics.
Description of the Related Art
RF electronics, such as cell phones, smart phones, tablets, computers, modems and other devices operate on a limited frequency spectrum. Various schemes are implemented to permit multiple devices to be transmitting and receiving on a particular frequency bands simultaneously. One such scheme is called carrier or channel aggregation which is currently used in 4G LTE Advanced implementations. In this scheme, wider transmission bandwidths are used to simultaneously transmit aggregated component carriers where the component carriers have different frequencies.
The component carriers can either be contiguous or non-contiguous frequencies. When multiple component carriers in different bands are aggregated and transmitted, they must be received using multiple bandpass filters, one for each band received. Such filters may be entirely independent from one another, or, coupled together at a common input point, such as at a common antenna.
Within the wireless receiving device, often the outputs of such filters must be amplified and re-combined onto a single path. An example of where this is done in a wireless device is the “diversity” receiver.
However, amplification and combining of these types of signals can result in significant noise and gain differences for signals among the different received frequency bands, which can affect overall signal quality. Hence, there is a need for an improved system and method of amplifying aggregated carrier component signals with reduced noise and improved gain characteristics.